A guard rail functions to align the wheels on railroad car axle sets to prevent damage to other trackwork components and to ensure that the wheel set tracks a particular path where a wheel may have a tendency to derail or where a derailment would be a particular safety hazard. Guard rails may be inserted in railroad trackwork adjacent the high side of curves, across bridges, adjacent turnout frogs and at elevated sections of trackwork for transit systems. At turnout frogs, guard rails are utilized to divert the path of one wheel of a railroad car axle set in such a manner as to cause the opposite wheel to be drawn away from the point of the turnout frog. If guard rails are not utilized at turnout frogs, a railroad car wheel passing through the frog, particularly a wheel which is worn, may strike the point of frog and thereby cause undesired wear or damage to the frog point as is well known in the art. Thus, a guard rail may be defined as a trackwork assembly which diverts or sets the path of one wheel of a railroad car axle set in such a manner as to cause the opposite wheel to track a desired path.
Traditionally guard rails have been non-adjustable and have required replacement when the guard rail face has worn to the point that it no longer properly guides the path of the non-guarded wheel of a railroad car axle set. Many guard rails have been formed from lengths of track rail which was laid parallel to the running rail to be guarded. Installation of the heavy track rail was difficult and somewhat imprecise. In many instances the guard rail assembly was mounted on the same tie plates as that of the traffic rail thus linking the installation points of the guard rail to the tie spacing.
In some instances, the guard rail has been fastened to the traffic rail. Such fastening often required drilling of the running rail in the field. This made installation of the guard rail difficult under the best of conditions and extremely difficult under adverse conditions such as bad weather or where electrical power was unavailable to the trackwork installation crew.
More recently, rolled steel guard bars have replaced sections of track rail in guard rail assemblies. The guard bars are mounted on a bracket or brace and provide a guard face which extends parallel to the gage line of a running rail. Inasmuch as the guard bars and the support brackets or braces are separate items only the guard bar has to be replaced when the guard face wears beyond an acceptable limit.
In most instances, guard rail assemblies do not have an adjustment which compensates for the wear of the guard face of a guard bar. In those assemblies which do provide an adjustment to compensate for wear of the guard face, the adjustment typically is awkward and requires a lengthy disassembly of the guard rail assembly.
Some non-adjustable guard rails are spiked directly to the wooden ties which support the tie plates for the traffic rails. However, in most instances adjustable and non-adjustable guard rail assemblies are secured to tie plates for traffic rails or directly to the traffic rails themselves by threaded fasteners or by welding. Threaded fasteners are disadvantageous inasmuch as they require a high level of maintenance due to their tendency to loosen over a period of time. As mentioned previously, those guard rail assemblies which are affixed to the running rail and require drilling of the running rail are extremely time consuming and difficult to install and maintain. Those guard rail assemblies which are spiked directly to railroad ties suffer from the disadvantage that over a period of time during which the guard rail assembly is replaced the railroad ties tend to become spike killed and must be replaced.
From the above, it may be observed that it is desirable to provide a guard rail assembly utilizing a replaceable guard bar which may be installed and adjusted easily without regard to tie spacing and which utilizes an elastic fastener.